I do think what you're trying to convey makes sense, and we could probably figure out some way to turn it into an acceptable flaw! I'm trying to think of some other things I can ask that might help you either develop her "rude" flaw into something a little less conditional, or else come up with an alternative you're happy with.
Do you not think something like "picky" would work with that? Picky about people and their behaviors? Picky about who she might like as her friends? Does she not like to be around certain types of people (like the mean, inconsiderate, and demanding types you mentioned)? Does she consider herself superior to other people at all? Even kind, encouraging people can possess a sense of superiority. They wouldn't necessarily think awful things about other people, just think that they're better than them (morally, socially, etc.)
Oh! Or, take her "Encouraging" virtue. The flip-side of that could make a new flaw. Does her encouragement ever lead to her being "Pushy"?
Shanyume
